From mboxrd@z Thu Jan  1 00:00:00 1970
From: Chao Peng <chao.p.peng@linux.intel.com>
Subject: Re: [PATCH v4 02/12] x86: improve psr scheduling code
Date: Fri, 10 Apr 2015 15:24:41 +0800
Message-ID: <20150410072441.GA3417@pengc-linux.bj.intel.com>
References: <1428571105-3604-1-git-send-email-chao.p.peng@linux.intel.com>
	<1428571105-3604-3-git-send-email-chao.p.peng@linux.intel.com>
	<5526E8C1.3060302@citrix.com>
Reply-To: Chao Peng <chao.p.peng@linux.intel.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
Content-Disposition: inline
In-Reply-To: <5526E8C1.3060302@citrix.com>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: keir@xen.org, Ian.Campbell@citrix.com, stefano.stabellini@eu.citrix.com, Ian.Jackson@eu.citrix.com, xen-devel@lists.xen.org, will.auld@intel.com, JBeulich@suse.com, wei.liu2@citrix.com, dgdegra@tycho.nsa.gov
List-Id: xen-devel@lists.xenproject.org

On Thu, Apr 09, 2015 at 10:01:53PM +0100, Andrew Cooper wrote:
> On 09/04/2015 10:18, Chao Peng wrote:
> > +static inline void psr_assoc_init(unsigned int cpu)
> > +{
> > +    struct psr_assoc *psra = &per_cpu(psr_assoc, cpu);
> > +
> > +    if ( psr_cmt_enabled() )
> > +        rdmsrl(MSR_IA32_PSR_ASSOC, psra->val);
> > +}
> 
> On further consideration, this would probably be better as a void
> function which used this_cpu() rather than per_cpu().
> 
> Absolutely nothing good can come of calling it with cpu !=
> smp_processor_id(), so we should avoid that situation arising in the
> first place.

Agreed.

> > +static void psr_cpu_init(unsigned int cpu)
> > +{
> > +    psr_assoc_init(cpu);
> > +}
> 
> This can also turn into a void helper.

This is, however, a little different. The next patch will add
cat_cpu_init() which will make use of this 'cpu' parameter. So do you
mean calling smp_processor_id() in cat_cpu_init() as well?

Thanks,
Chao